Description
Key Characters:
Growth Form:
Plants coarse and stout, glabrous perennial herbs of wet or swampy habitats, with extensive starchy creeping rhizomes, often forming large dense colonies.
Stems:
Stems erect, 2.5–4 m long, unbranched, terminating in an inflorescence.
Roots:
Fibrous root system.
Leaves:
Leaves simple.
Alternate, distichous and erect.
Blades linear, nearly all basal, blades flattened, usually spongy in texture, with longitudinal partitions connecting the upper and lower surfaces, and numerous cross partitions connecting the longitudinal ones; leaves 6–9(–12) per vegetative stem, pale yellowish green, flat but moderately concave on lower surface, 6–12(–15) mm wide.
Surfaces glabrous.
Margins entire.
Veins parallel.
Sheaths usually opened at the throat with scarious margins tapering to the blade.
Stipules absent.
Flowers:
Flowers numerous in dense, cylindrical, complex spikes, staminate spikes above pistillate ones, the spikes contiguous or separated, most of the flowers axillary to short bristle-like bracts.
Flowers unisexual; Staminate and pistillate spikes separated by an interval (0.5–)2–6 cm long; staminate spikes whitish brown, with linear scales, these usually laciniate at apex, stamens on branched filaments, pollen golden yellow, in monads; pistillate spikes pale brown, 15–25 cm long, 1.5–2.5 cm in diameter, each flower with fragile, translucent, obovate scales exceeding the gynophore hairs.
Calyx (sepals) absent.
Corolla (petals) absent.
Stamens 1–3 in staminate flowers, absent in pistillate flowers.
Fruit:
Fruit small; dry; tardily dehiscent; wind–dispersed; ellipsoid; 0.8–1.1 mm long.
Seeds with a slender; cylindrical embryo surrounded by copious mealy endosperm and thin perisperm.
Ploidy:
2n = 30
Habitat:
Marshes.
Elevation Range: